The formula is:
=WORKDAY(D7,C7,[Optional list of Holidays])
which you put in D8 and then drag down.
Your cells have to be in a Date format.
The help file says for the Holidays list:
- Holidays Optional. An optional list of one or more dates to exclude from the working calendar, such as state and federal holidays and floating holidays. The list can be either a range of cells that contain the dates or an array constant (array: Used to build single formulas that produce multiple results or that operate on a group of arguments that are arranged in rows and columns. An array range shares a common formula; an array constant is a group of constants used as an argument.) of the serial numbers that represent the dates.
Note that in your example, there is no holiday between 2/22/2011 and 2/24/2011, so D17 should be 2/24/2011, and the others modified from there. Also D20 is not 10 days from 2/28/2011.